AP Physics 2‎ > ‎Unit 3‎ > ‎Kinetic Theory‎ > ‎

Maxwell Distribution Lab

Maxwell-Boltzmann Distribution Lab

Purpose:

In this activity you will be looking at the distribution of speeds in a container of an ideal gas.

Procedure:

Part 1:  Qualitative Introduction

  1. Take at your periodic table and take a gander at your noble gases.  Keep this out for consultation for this entire lab.

  2. Open up the program found here.

  3. Give a sketch of your box of atoms and show the directions of a few of the atoms.

  4. Scroll through your different gases, taking note of the speed of the atoms in the box.  Make a qualitative statement about the relationship between the mass of the particle and the speed of the particle at a given temperature.

  5. Set your gas to Argon and scroll through all possible temperatures.  Make sure you see the motion of the molecules at lowest temperature offered in your program and the highest temperature offered in your program.  Make a qualitative statement about the relationship between the temperature of the sample and the speed of the particles.

  6. Set your gas to Xenon and your temperature to the lowest temperature available for your program.  The graph at the bottom shows the likelihood of finding atoms at a give speed in your sample.  The higher the point on the graph for a given temperature, the more likely you are to find an atom at the particular speed.  Discuss the likelihood of finding atoms at speeds greater than 300 m/s in a sample of Xenon at low temperatures.

  7. With your gas still on Xenon, scroll through all the range of temperatures available to you.  Look at how your graph changes as temperature rises.  Describe what happens to the size of the spread of likely speeds as the temperature of a sample of gas atoms increases.

  8. With your gas still set on Xenon, return to the lowest available temperature.  Save the plot.  Then raise the temperature to just over 100K and save that plot.  Then raise the temperature to just over 200K and save that plot.  Finally, get to the highest temperature.  With all 4 plots visible, carefully transfer this graph to your lab book.  Make sure you have a key to your graph.

  9. Set your gas to Helium and the temperature to the lowest possible value.  Save the plot.  Now cycle through all the different noble gases and save the plot for each.    With all plots visible, carefully transfer this graph to your lab book.  Make sure you have a key to your graph.

Part 2:  Quantitative study of Temperature and Speed

  1. Set your sample to Krypton and your temperature to its lowest value.

  2. Create a data table that shows the sample's temperature, the most likely speed (peak of graph), and the kinetic energy of the atom with this peak speed.

  3. Record data for ten of the available temperatures.  Make sure you get a good range of temperatures including your lowest and highest available temperatures.

  4. Use this program to plot a speed vs. temperature and then a graph of KE vs temperature.  Transfer both graphs and equations into your lab book.

Part 3:  Quantitative study of Mass and KE

  1. Set your sample to Neon and your temperature to somewhere around 100 K.

  2. Create a data table that shows the sample's mass, the most likely speed (peak of graph), and the kinetic energy of the atom with this peak speed.

  3. Record data for all different elements with a mass greater than Neon.

  4. Use this program to plot a speed vs. mass and then a graph of KE vs mass.  Transfer both graphs and equations into your lab book.
Stuff to have in your lab book:
  1. Purpose
  2. Picture of the lab setup
  3. Data Table
  4. Graph and equation
  5. Conclusion
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